Test items relating to Project Physics Unit 3 are presented in this booklet. Included are 70 multiple-choice and 20 problem-and-essay questions. Concepts of mechanics are examined on energy, momentum, kinetic theory of gases, pulse analyses, "heat death," water waves, power, conservation laws, normal distribution, thermodynamic laws, and wave reflection, refraction, interference, and diffraction. Suggestions are made for time consumption in answering some items. Besides directions and illustrations for explanation purposes, related physical constants, units, and equations are provided. The work of Harvard Project Physics has been financially supported by: the Carnegie Corporation of New York, the Ford Foundation, the National Science Foundation, the Alfred P. Sloan Foundation, the United States Office of Education, and Harvard University. (CC)